Accuphase e202 right channel quiet

[jj0b]

Hello,

I just got an Accuphase e202 that worked great for a couple weeks (other than a crackly volume pot) but I just noticed today that my right output channel is not as powerful as my left.

I have switched my speakers around and tried all the different output mode combinations but the output from the left channel is always about 10dB lower. (as read off the VU meters)

I have copies of the schematics but don't know where to start my trouble shooting.

Could anyone offer some advice on where to start with solving this problem.

Any input is much appreciated.

 

[jj0b]

If no one has any specific advice on troubleshooting a quiet channel on an accuphase e202 can anyone recommend any online resources where I could learn about troubleshooting an audio amplifier in general?

I'm just wondering what kind of faults to look for and which components might usually be responsible for such a problem.

Thanks.

 

[analogwonder]

I got an used E-202 recently; it is functioning with one fuse lamp burned out. I figured out that the contacts of the selector switches are not so good. I think this is reasonable since the amp is built more than 30 years ago. You can play with the switches and see if you can find anything wrong in the switches. I openned the chassis today trying to figure out the type of fuse lamp and also figured out that it is not easy to service this amp since it is so old. I could not pull out the power amp circuit board. Would you please share the schematic with me? I am curious about the mid-size electrolytic cap sitting on the power amp PCB.

 

[Jan Dupont]

You can find the complete Service Manual here:
www.audio-circuit.dk Free Downloads
If the fault is present whatever input you select, I wouldn't suspect the switch......
It's more likely (and happely) just a bad solder or a faulty component which can be fixed with a new........

 

[jj0b]

Yes, the fault is present no matter which input so I expect it is a component or solder joint.

Which part of the circuit would be a likely place to start and which components would be likely culprits when the symptom is a quieter signal out of one channel?

Can I do this kind of trouble shooting with a multimeter or do I need to dig out an oscilloscope?

Thanks!

 

[Jan Dupont]

As I recall you can separate the pre and poweramp on the back side ?
If so start by finding out if it is the pre or poweramp that has the fault.....
It can be difficult to find a fault like this with a multimeter, however you can be lucky.
There are written some DC readings different places in the circuit on the schematic in the service manual. Start there and let us know.

 

[jj0b]

Thank you Jan, I will post my findings here.